Gym once a week, pointless?

[Beknown]

I use to do weight lifting at the gym 3 times a week, combined with a good diet I saw good results and was very happy. These days I have less free time on my hands (other hobbies, sports, family, girlfriend, time away with work etc.) but I think I can manage one high intensity session each week, probably your typical stronglift 5x5 or similar.

Is this worth doing or am I wasting my time? I am not expecting to see hypertrophy gains but it's more a case of maybe keeping things in slightly better shape than they would be, retaining some strength and expelling some built up energy.